The purpose of this research is to investigate the naturally occurring diseases of laboratory animals by clinical, clinical pathologic and pathologic (gross and microscopic morbid anatomy) means. Support for this project provides in part for the professional and technical personnel and supplies to enable the Animal Disease Diagnostic Laboratory (ADDL) to carry out this mission for the primary benefit of investigators using animals at the University of Rochester. Information gained in these studies enable the investigators at this institution to better evaluate the validity of data obtained from their experimental animals. In addition, it is hoped that methods will be developed for detecting subclinical disease in laboratory animals. The investigators also hope to be able to identify naturally occurring disease in laboratory animals which may serve as useful models for the study of human disease.